Fitting
Installation:
Be careful
not to over tighten poly fittings. If over tightened, these fittings
can be damaged and leak. In such cases, always replace the fittings.
If thread sealant is used, be certain that it is rated for use with
the fittings and chemical to be contained. Never subject fittings
to loads or weight that may cause cracking. Avoid rigid plumbing
from tank fitting. Fitting installations to and from tank must consider
the effects of expansion and contraction stresses due to temperature
as well as filling and emptying of the tank.
Caution:
Be particularly careful with fittings that are friction welded,
often referred to as "spinwelds". These fittings can fail
if attachments are not properly supported, are exposed to excessive
vibration or are over tightened. Never hang long lengths of hose
or pipe without support hangers to carry the dead weight of the
hose or pipe. Filters, valves and couplings will need to be supported
as well so the loads are not transferred to the "spinweld"
fitting.
Dry Fittings - Fittings that are not exposed
to chemicals and have no low
temperature limit providing the plumbing loads that the fittings
are subjected to
are within the Application Guidelines
recommendations.
Wet Fittings - Fittings that are exposed to
chemicals will have a low temperature
rating equivalent to the freezing limits of the chemical
the fitting is exposed to. In
the case of water that would be 32F ambient. Chemicals
or solutions such as
calcium chloride are generally rated for -20F (depending
upon the salt
concentration). Note that heaters, heat bands or chemical
inhibitors that prevent
chemical freeze point up will allow the fittings to be exposed
to ambient
temperatures below the published freeze point of the chemical.
Again, the low
temperature rating of all fittings must be above the point
at which the chemicals
freeze or solidify.
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